Figure 10: Proteolytic activity profiles from A. castellanii and A. polyphaga. 1 μg of protein was analyzed from total extracts, which is equivalent to 3.6 × 103 trophozoites. The extracts were obtained from axenic cultures of A. castellanii and A. polyphaga; these were analyzed on SDS PAGE gels copolymerized with gelatin and incubated in the presence of protease inhibitors with the following concentrations: 20 mM NEM, 100 mM EDTA, and 1 mM PMSF. Protease analysis represents the mean of 5 separate experiments.